xref: /linux/drivers/virtio/virtio_pci_modern_dev.c (revision 0e9ab8e4d44ae9d9aaf213bfd2c90bbe7289337b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 #include <linux/virtio_pci_modern.h>
4 #include <linux/module.h>
5 #include <linux/pci.h>
6 #include <linux/delay.h>
7 
8 /*
9  * vp_modern_map_capability - map a part of virtio pci capability
10  * @mdev: the modern virtio-pci device
11  * @off: offset of the capability
12  * @minlen: minimal length of the capability
13  * @align: align requirement
14  * @start: start from the capability
15  * @size: map size
16  * @len: the length that is actually mapped
17  * @pa: physical address of the capability
18  *
19  * Returns the io address of for the part of the capability
20  */
21 static void __iomem *
22 vp_modern_map_capability(struct virtio_pci_modern_device *mdev, int off,
23 			 size_t minlen, u32 align, u32 start, u32 size,
24 			 size_t *len, resource_size_t *pa)
25 {
26 	struct pci_dev *dev = mdev->pci_dev;
27 	u8 bar;
28 	u32 offset, length;
29 	void __iomem *p;
30 
31 	pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
32 						 bar),
33 			     &bar);
34 	pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
35 			     &offset);
36 	pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
37 			      &length);
38 
39 	/* Check if the BAR may have changed since we requested the region. */
40 	if (bar >= PCI_STD_NUM_BARS || !(mdev->modern_bars & (1 << bar))) {
41 		dev_err(&dev->dev,
42 			"virtio_pci: bar unexpectedly changed to %u\n", bar);
43 		return NULL;
44 	}
45 
46 	if (length <= start) {
47 		dev_err(&dev->dev,
48 			"virtio_pci: bad capability len %u (>%u expected)\n",
49 			length, start);
50 		return NULL;
51 	}
52 
53 	if (length - start < minlen) {
54 		dev_err(&dev->dev,
55 			"virtio_pci: bad capability len %u (>=%zu expected)\n",
56 			length, minlen);
57 		return NULL;
58 	}
59 
60 	length -= start;
61 
62 	if (start + offset < offset) {
63 		dev_err(&dev->dev,
64 			"virtio_pci: map wrap-around %u+%u\n",
65 			start, offset);
66 		return NULL;
67 	}
68 
69 	offset += start;
70 
71 	if (offset & (align - 1)) {
72 		dev_err(&dev->dev,
73 			"virtio_pci: offset %u not aligned to %u\n",
74 			offset, align);
75 		return NULL;
76 	}
77 
78 	if (length > size)
79 		length = size;
80 
81 	if (len)
82 		*len = length;
83 
84 	if (minlen + offset < minlen ||
85 	    minlen + offset > pci_resource_len(dev, bar)) {
86 		dev_err(&dev->dev,
87 			"virtio_pci: map virtio %zu@%u "
88 			"out of range on bar %i length %lu\n",
89 			minlen, offset,
90 			bar, (unsigned long)pci_resource_len(dev, bar));
91 		return NULL;
92 	}
93 
94 	p = pci_iomap_range(dev, bar, offset, length);
95 	if (!p)
96 		dev_err(&dev->dev,
97 			"virtio_pci: unable to map virtio %u@%u on bar %i\n",
98 			length, offset, bar);
99 	else if (pa)
100 		*pa = pci_resource_start(dev, bar) + offset;
101 
102 	return p;
103 }
104 
105 /**
106  * virtio_pci_find_capability - walk capabilities to find device info.
107  * @dev: the pci device
108  * @cfg_type: the VIRTIO_PCI_CAP_* value we seek
109  * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO.
110  * @bars: the bitmask of BARs
111  *
112  * Returns offset of the capability, or 0.
113  */
114 static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
115 					     u32 ioresource_types, int *bars)
116 {
117 	int pos;
118 
119 	for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
120 	     pos > 0;
121 	     pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
122 		u8 type, bar;
123 		pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
124 							 cfg_type),
125 				     &type);
126 		pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
127 							 bar),
128 				     &bar);
129 
130 		/* Ignore structures with reserved BAR values */
131 		if (bar >= PCI_STD_NUM_BARS)
132 			continue;
133 
134 		if (type == cfg_type) {
135 			if (pci_resource_len(dev, bar) &&
136 			    pci_resource_flags(dev, bar) & ioresource_types) {
137 				*bars |= (1 << bar);
138 				return pos;
139 			}
140 		}
141 	}
142 	return 0;
143 }
144 
145 /* This is part of the ABI.  Don't screw with it. */
146 static inline void check_offsets(void)
147 {
148 	/* Note: disk space was harmed in compilation of this function. */
149 	BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
150 		     offsetof(struct virtio_pci_cap, cap_vndr));
151 	BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
152 		     offsetof(struct virtio_pci_cap, cap_next));
153 	BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
154 		     offsetof(struct virtio_pci_cap, cap_len));
155 	BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE !=
156 		     offsetof(struct virtio_pci_cap, cfg_type));
157 	BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR !=
158 		     offsetof(struct virtio_pci_cap, bar));
159 	BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
160 		     offsetof(struct virtio_pci_cap, offset));
161 	BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
162 		     offsetof(struct virtio_pci_cap, length));
163 	BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
164 		     offsetof(struct virtio_pci_notify_cap,
165 			      notify_off_multiplier));
166 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
167 		     offsetof(struct virtio_pci_common_cfg,
168 			      device_feature_select));
169 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
170 		     offsetof(struct virtio_pci_common_cfg, device_feature));
171 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
172 		     offsetof(struct virtio_pci_common_cfg,
173 			      guest_feature_select));
174 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
175 		     offsetof(struct virtio_pci_common_cfg, guest_feature));
176 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
177 		     offsetof(struct virtio_pci_common_cfg, msix_config));
178 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
179 		     offsetof(struct virtio_pci_common_cfg, num_queues));
180 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
181 		     offsetof(struct virtio_pci_common_cfg, device_status));
182 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION !=
183 		     offsetof(struct virtio_pci_common_cfg, config_generation));
184 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
185 		     offsetof(struct virtio_pci_common_cfg, queue_select));
186 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
187 		     offsetof(struct virtio_pci_common_cfg, queue_size));
188 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
189 		     offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
190 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
191 		     offsetof(struct virtio_pci_common_cfg, queue_enable));
192 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
193 		     offsetof(struct virtio_pci_common_cfg, queue_notify_off));
194 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
195 		     offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
196 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !=
197 		     offsetof(struct virtio_pci_common_cfg, queue_desc_hi));
198 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !=
199 		     offsetof(struct virtio_pci_common_cfg, queue_avail_lo));
200 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !=
201 		     offsetof(struct virtio_pci_common_cfg, queue_avail_hi));
202 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !=
203 		     offsetof(struct virtio_pci_common_cfg, queue_used_lo));
204 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !=
205 		     offsetof(struct virtio_pci_common_cfg, queue_used_hi));
206 }
207 
208 /*
209  * vp_modern_probe: probe the modern virtio pci device, note that the
210  * caller is required to enable PCI device before calling this function.
211  * @mdev: the modern virtio-pci device
212  *
213  * Return 0 on succeed otherwise fail
214  */
215 int vp_modern_probe(struct virtio_pci_modern_device *mdev)
216 {
217 	struct pci_dev *pci_dev = mdev->pci_dev;
218 	int err, common, isr, notify, device;
219 	u32 notify_length;
220 	u32 notify_offset;
221 
222 	check_offsets();
223 
224 	/* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
225 	if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
226 		return -ENODEV;
227 
228 	if (pci_dev->device < 0x1040) {
229 		/* Transitional devices: use the PCI subsystem device id as
230 		 * virtio device id, same as legacy driver always did.
231 		 */
232 		mdev->id.device = pci_dev->subsystem_device;
233 	} else {
234 		/* Modern devices: simply use PCI device id, but start from 0x1040. */
235 		mdev->id.device = pci_dev->device - 0x1040;
236 	}
237 	mdev->id.vendor = pci_dev->subsystem_vendor;
238 
239 	/* check for a common config: if not, use legacy mode (bar 0). */
240 	common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
241 					    IORESOURCE_IO | IORESOURCE_MEM,
242 					    &mdev->modern_bars);
243 	if (!common) {
244 		dev_info(&pci_dev->dev,
245 			 "virtio_pci: leaving for legacy driver\n");
246 		return -ENODEV;
247 	}
248 
249 	/* If common is there, these should be too... */
250 	isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
251 					 IORESOURCE_IO | IORESOURCE_MEM,
252 					 &mdev->modern_bars);
253 	notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
254 					    IORESOURCE_IO | IORESOURCE_MEM,
255 					    &mdev->modern_bars);
256 	if (!isr || !notify) {
257 		dev_err(&pci_dev->dev,
258 			"virtio_pci: missing capabilities %i/%i/%i\n",
259 			common, isr, notify);
260 		return -EINVAL;
261 	}
262 
263 	err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64));
264 	if (err)
265 		err = dma_set_mask_and_coherent(&pci_dev->dev,
266 						DMA_BIT_MASK(32));
267 	if (err)
268 		dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA.  Trying to continue, but this might not work.\n");
269 
270 	/* Device capability is only mandatory for devices that have
271 	 * device-specific configuration.
272 	 */
273 	device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
274 					    IORESOURCE_IO | IORESOURCE_MEM,
275 					    &mdev->modern_bars);
276 
277 	err = pci_request_selected_regions(pci_dev, mdev->modern_bars,
278 					   "virtio-pci-modern");
279 	if (err)
280 		return err;
281 
282 	err = -EINVAL;
283 	mdev->common = vp_modern_map_capability(mdev, common,
284 				      sizeof(struct virtio_pci_common_cfg), 4,
285 				      0, sizeof(struct virtio_pci_common_cfg),
286 				      NULL, NULL);
287 	if (!mdev->common)
288 		goto err_map_common;
289 	mdev->isr = vp_modern_map_capability(mdev, isr, sizeof(u8), 1,
290 					     0, 1,
291 					     NULL, NULL);
292 	if (!mdev->isr)
293 		goto err_map_isr;
294 
295 	/* Read notify_off_multiplier from config space. */
296 	pci_read_config_dword(pci_dev,
297 			      notify + offsetof(struct virtio_pci_notify_cap,
298 						notify_off_multiplier),
299 			      &mdev->notify_offset_multiplier);
300 	/* Read notify length and offset from config space. */
301 	pci_read_config_dword(pci_dev,
302 			      notify + offsetof(struct virtio_pci_notify_cap,
303 						cap.length),
304 			      &notify_length);
305 
306 	pci_read_config_dword(pci_dev,
307 			      notify + offsetof(struct virtio_pci_notify_cap,
308 						cap.offset),
309 			      &notify_offset);
310 
311 	/* We don't know how many VQs we'll map, ahead of the time.
312 	 * If notify length is small, map it all now.
313 	 * Otherwise, map each VQ individually later.
314 	 */
315 	if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
316 		mdev->notify_base = vp_modern_map_capability(mdev, notify,
317 							     2, 2,
318 							     0, notify_length,
319 							     &mdev->notify_len,
320 							     &mdev->notify_pa);
321 		if (!mdev->notify_base)
322 			goto err_map_notify;
323 	} else {
324 		mdev->notify_map_cap = notify;
325 	}
326 
327 	/* Again, we don't know how much we should map, but PAGE_SIZE
328 	 * is more than enough for all existing devices.
329 	 */
330 	if (device) {
331 		mdev->device = vp_modern_map_capability(mdev, device, 0, 4,
332 							0, PAGE_SIZE,
333 							&mdev->device_len,
334 							NULL);
335 		if (!mdev->device)
336 			goto err_map_device;
337 	}
338 
339 	return 0;
340 
341 err_map_device:
342 	if (mdev->notify_base)
343 		pci_iounmap(pci_dev, mdev->notify_base);
344 err_map_notify:
345 	pci_iounmap(pci_dev, mdev->isr);
346 err_map_isr:
347 	pci_iounmap(pci_dev, mdev->common);
348 err_map_common:
349 	pci_release_selected_regions(pci_dev, mdev->modern_bars);
350 	return err;
351 }
352 EXPORT_SYMBOL_GPL(vp_modern_probe);
353 
354 /*
355  * vp_modern_remove: remove and cleanup the modern virtio pci device
356  * @mdev: the modern virtio-pci device
357  */
358 void vp_modern_remove(struct virtio_pci_modern_device *mdev)
359 {
360 	struct pci_dev *pci_dev = mdev->pci_dev;
361 
362 	if (mdev->device)
363 		pci_iounmap(pci_dev, mdev->device);
364 	if (mdev->notify_base)
365 		pci_iounmap(pci_dev, mdev->notify_base);
366 	pci_iounmap(pci_dev, mdev->isr);
367 	pci_iounmap(pci_dev, mdev->common);
368 	pci_release_selected_regions(pci_dev, mdev->modern_bars);
369 }
370 EXPORT_SYMBOL_GPL(vp_modern_remove);
371 
372 /*
373  * vp_modern_get_features - get features from device
374  * @mdev: the modern virtio-pci device
375  *
376  * Returns the features read from the device
377  */
378 u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev)
379 {
380 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
381 
382 	u64 features;
383 
384 	vp_iowrite32(0, &cfg->device_feature_select);
385 	features = vp_ioread32(&cfg->device_feature);
386 	vp_iowrite32(1, &cfg->device_feature_select);
387 	features |= ((u64)vp_ioread32(&cfg->device_feature) << 32);
388 
389 	return features;
390 }
391 EXPORT_SYMBOL_GPL(vp_modern_get_features);
392 
393 /*
394  * vp_modern_get_driver_features - get driver features from device
395  * @mdev: the modern virtio-pci device
396  *
397  * Returns the driver features read from the device
398  */
399 u64 vp_modern_get_driver_features(struct virtio_pci_modern_device *mdev)
400 {
401 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
402 
403 	u64 features;
404 
405 	vp_iowrite32(0, &cfg->guest_feature_select);
406 	features = vp_ioread32(&cfg->guest_feature);
407 	vp_iowrite32(1, &cfg->guest_feature_select);
408 	features |= ((u64)vp_ioread32(&cfg->guest_feature) << 32);
409 
410 	return features;
411 }
412 EXPORT_SYMBOL_GPL(vp_modern_get_driver_features);
413 
414 /*
415  * vp_modern_set_features - set features to device
416  * @mdev: the modern virtio-pci device
417  * @features: the features set to device
418  */
419 void vp_modern_set_features(struct virtio_pci_modern_device *mdev,
420 			    u64 features)
421 {
422 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
423 
424 	vp_iowrite32(0, &cfg->guest_feature_select);
425 	vp_iowrite32((u32)features, &cfg->guest_feature);
426 	vp_iowrite32(1, &cfg->guest_feature_select);
427 	vp_iowrite32(features >> 32, &cfg->guest_feature);
428 }
429 EXPORT_SYMBOL_GPL(vp_modern_set_features);
430 
431 /*
432  * vp_modern_generation - get the device genreation
433  * @mdev: the modern virtio-pci device
434  *
435  * Returns the genreation read from device
436  */
437 u32 vp_modern_generation(struct virtio_pci_modern_device *mdev)
438 {
439 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
440 
441 	return vp_ioread8(&cfg->config_generation);
442 }
443 EXPORT_SYMBOL_GPL(vp_modern_generation);
444 
445 /*
446  * vp_modern_get_status - get the device status
447  * @mdev: the modern virtio-pci device
448  *
449  * Returns the status read from device
450  */
451 u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev)
452 {
453 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
454 
455 	return vp_ioread8(&cfg->device_status);
456 }
457 EXPORT_SYMBOL_GPL(vp_modern_get_status);
458 
459 /*
460  * vp_modern_set_status - set status to device
461  * @mdev: the modern virtio-pci device
462  * @status: the status set to device
463  */
464 void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
465 				 u8 status)
466 {
467 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
468 
469 	/*
470 	 * Per memory-barriers.txt, wmb() is not needed to guarantee
471 	 * that the cache coherent memory writes have completed
472 	 * before writing to the MMIO region.
473 	 */
474 	vp_iowrite8(status, &cfg->device_status);
475 }
476 EXPORT_SYMBOL_GPL(vp_modern_set_status);
477 
478 /*
479  * vp_modern_get_queue_reset - get the queue reset status
480  * @mdev: the modern virtio-pci device
481  * @index: queue index
482  */
483 int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
484 {
485 	struct virtio_pci_modern_common_cfg __iomem *cfg;
486 
487 	cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
488 
489 	vp_iowrite16(index, &cfg->cfg.queue_select);
490 	return vp_ioread16(&cfg->queue_reset);
491 }
492 EXPORT_SYMBOL_GPL(vp_modern_get_queue_reset);
493 
494 /*
495  * vp_modern_set_queue_reset - reset the queue
496  * @mdev: the modern virtio-pci device
497  * @index: queue index
498  */
499 void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
500 {
501 	struct virtio_pci_modern_common_cfg __iomem *cfg;
502 
503 	cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
504 
505 	vp_iowrite16(index, &cfg->cfg.queue_select);
506 	vp_iowrite16(1, &cfg->queue_reset);
507 
508 	while (vp_ioread16(&cfg->queue_reset))
509 		msleep(1);
510 
511 	while (vp_ioread16(&cfg->cfg.queue_enable))
512 		msleep(1);
513 }
514 EXPORT_SYMBOL_GPL(vp_modern_set_queue_reset);
515 
516 /*
517  * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
518  * @mdev: the modern virtio-pci device
519  * @index: queue index
520  * @vector: the config vector
521  *
522  * Returns the config vector read from the device
523  */
524 u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev,
525 			   u16 index, u16 vector)
526 {
527 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
528 
529 	vp_iowrite16(index, &cfg->queue_select);
530 	vp_iowrite16(vector, &cfg->queue_msix_vector);
531 	/* Flush the write out to device */
532 	return vp_ioread16(&cfg->queue_msix_vector);
533 }
534 EXPORT_SYMBOL_GPL(vp_modern_queue_vector);
535 
536 /*
537  * vp_modern_config_vector - set the vector for config interrupt
538  * @mdev: the modern virtio-pci device
539  * @vector: the config vector
540  *
541  * Returns the config vector read from the device
542  */
543 u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev,
544 			    u16 vector)
545 {
546 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
547 
548 	/* Setup the vector used for configuration events */
549 	vp_iowrite16(vector, &cfg->msix_config);
550 	/* Verify we had enough resources to assign the vector */
551 	/* Will also flush the write out to device */
552 	return vp_ioread16(&cfg->msix_config);
553 }
554 EXPORT_SYMBOL_GPL(vp_modern_config_vector);
555 
556 /*
557  * vp_modern_queue_address - set the virtqueue address
558  * @mdev: the modern virtio-pci device
559  * @index: the queue index
560  * @desc_addr: address of the descriptor area
561  * @driver_addr: address of the driver area
562  * @device_addr: address of the device area
563  */
564 void vp_modern_queue_address(struct virtio_pci_modern_device *mdev,
565 			     u16 index, u64 desc_addr, u64 driver_addr,
566 			     u64 device_addr)
567 {
568 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
569 
570 	vp_iowrite16(index, &cfg->queue_select);
571 
572 	vp_iowrite64_twopart(desc_addr, &cfg->queue_desc_lo,
573 			     &cfg->queue_desc_hi);
574 	vp_iowrite64_twopart(driver_addr, &cfg->queue_avail_lo,
575 			     &cfg->queue_avail_hi);
576 	vp_iowrite64_twopart(device_addr, &cfg->queue_used_lo,
577 			     &cfg->queue_used_hi);
578 }
579 EXPORT_SYMBOL_GPL(vp_modern_queue_address);
580 
581 /*
582  * vp_modern_set_queue_enable - enable a virtqueue
583  * @mdev: the modern virtio-pci device
584  * @index: the queue index
585  * @enable: whether the virtqueue is enable or not
586  */
587 void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev,
588 				u16 index, bool enable)
589 {
590 	vp_iowrite16(index, &mdev->common->queue_select);
591 	vp_iowrite16(enable, &mdev->common->queue_enable);
592 }
593 EXPORT_SYMBOL_GPL(vp_modern_set_queue_enable);
594 
595 /*
596  * vp_modern_get_queue_enable - enable a virtqueue
597  * @mdev: the modern virtio-pci device
598  * @index: the queue index
599  *
600  * Returns whether a virtqueue is enabled or not
601  */
602 bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev,
603 				u16 index)
604 {
605 	vp_iowrite16(index, &mdev->common->queue_select);
606 
607 	return vp_ioread16(&mdev->common->queue_enable);
608 }
609 EXPORT_SYMBOL_GPL(vp_modern_get_queue_enable);
610 
611 /*
612  * vp_modern_set_queue_size - set size for a virtqueue
613  * @mdev: the modern virtio-pci device
614  * @index: the queue index
615  * @size: the size of the virtqueue
616  */
617 void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev,
618 			      u16 index, u16 size)
619 {
620 	vp_iowrite16(index, &mdev->common->queue_select);
621 	vp_iowrite16(size, &mdev->common->queue_size);
622 
623 }
624 EXPORT_SYMBOL_GPL(vp_modern_set_queue_size);
625 
626 /*
627  * vp_modern_get_queue_size - get size for a virtqueue
628  * @mdev: the modern virtio-pci device
629  * @index: the queue index
630  *
631  * Returns the size of the virtqueue
632  */
633 u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev,
634 			     u16 index)
635 {
636 	vp_iowrite16(index, &mdev->common->queue_select);
637 
638 	return vp_ioread16(&mdev->common->queue_size);
639 
640 }
641 EXPORT_SYMBOL_GPL(vp_modern_get_queue_size);
642 
643 /*
644  * vp_modern_get_num_queues - get the number of virtqueues
645  * @mdev: the modern virtio-pci device
646  *
647  * Returns the number of virtqueues
648  */
649 u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev)
650 {
651 	return vp_ioread16(&mdev->common->num_queues);
652 }
653 EXPORT_SYMBOL_GPL(vp_modern_get_num_queues);
654 
655 /*
656  * vp_modern_get_queue_notify_off - get notification offset for a virtqueue
657  * @mdev: the modern virtio-pci device
658  * @index: the queue index
659  *
660  * Returns the notification offset for a virtqueue
661  */
662 static u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev,
663 					  u16 index)
664 {
665 	vp_iowrite16(index, &mdev->common->queue_select);
666 
667 	return vp_ioread16(&mdev->common->queue_notify_off);
668 }
669 
670 /*
671  * vp_modern_map_vq_notify - map notification area for a
672  * specific virtqueue
673  * @mdev: the modern virtio-pci device
674  * @index: the queue index
675  * @pa: the pointer to the physical address of the nofity area
676  *
677  * Returns the address of the notification area
678  */
679 void __iomem *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
680 				      u16 index, resource_size_t *pa)
681 {
682 	u16 off = vp_modern_get_queue_notify_off(mdev, index);
683 
684 	if (mdev->notify_base) {
685 		/* offset should not wrap */
686 		if ((u64)off * mdev->notify_offset_multiplier + 2
687 			> mdev->notify_len) {
688 			dev_warn(&mdev->pci_dev->dev,
689 				 "bad notification offset %u (x %u) "
690 				 "for queue %u > %zd",
691 				 off, mdev->notify_offset_multiplier,
692 				 index, mdev->notify_len);
693 			return NULL;
694 		}
695 		if (pa)
696 			*pa = mdev->notify_pa +
697 			      off * mdev->notify_offset_multiplier;
698 		return mdev->notify_base + off * mdev->notify_offset_multiplier;
699 	} else {
700 		return vp_modern_map_capability(mdev,
701 				       mdev->notify_map_cap, 2, 2,
702 				       off * mdev->notify_offset_multiplier, 2,
703 				       NULL, pa);
704 	}
705 }
706 EXPORT_SYMBOL_GPL(vp_modern_map_vq_notify);
707 
708 MODULE_VERSION("0.1");
709 MODULE_DESCRIPTION("Modern Virtio PCI Device");
710 MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
711 MODULE_LICENSE("GPL");
712